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Guide to NAICS & SIC Codes

What are NAICS & SIC Codes?

  • NAICS and SIC codes help classify and measure industry activity.
  • By knowing the NAICS and/or SIC code for a company, you will be able to locate information about its industry and competitors in library databases, books, and on the Internet.
  • Even though the codes are standardized, resources will assign codes differently. Many companies can have multiple codes because of their various business segments. Be flexible and cautious when using codes to search, and always check multiple sources.

Reading a NAICS Code

The NAICS is arranged in a hierarchical structure. The first two digits identify a major Economic Sector, the third digit designates an Economic Subsector, the fourth digit designates an Industry Group, and the fifth digit designates the NAICS Industry.


Souce: U.S Census Bureau, NAICS Code

Reading a SIC Code

The first two digits of the code identify the major industry group, the third digit identifies the industry group and the fourth digit identifies the industry.

SIC code

Souce: NAICS Association, How to you read an SIC Code?